This invention relates to multi-unit rotary mechanisms of the type disclosed in U.S. Pat. No. 2,988,065, granted June 13, 1961, to Wankel et al, and particularly to such an engine designed for operation as a stratified charge engine, for example, as disclosed in U.S. Pat. No. 3,246,636, granted Apr. 19, 1966 to Bentele and U.S. Pat. No. 3,894,518, granted July 15, 1975 to Gavrun et al.
In multi-unit, rotary piston mechanisms comprising more than two units (a unit being one rotor supported on a mainshaft for planetary rotation in a housing cavity and the housing cavity defining the cavity) such as exemplified in U.S. Pat. No. 3,077,867, granted Feb. 19, 1963, to Froede et al, are utilized when it is desired to provide increased power output by combining a plurality of rotary units into a single power plant. Preferably, such multiple rotary engine power plants should have a uniform interval between the firing of the working chambers, axially aligned positions for both the inlet and outlet passages of the rotary engine units as well as maximizing the commonality of parts.
One form of triple rotor engine can be made by combining a conventional "stand-alone" two-unit rotary engine; that is, an engine which is independently functionally operative without the necessity of modifications such as changes in engine balance or ignition interval, with a single unit engine. Such a conventional stand-alone two-unit engine would have its rotor eccentrics offset by 180 degrees in order to provide uniform intervals between the firing of the working chambers as is exemplified in the two-unit rotary engines of the aforementioned Froede et al patent. Coupling such a two-unit rotary engine to another single unit rotary engine will inherently result in a triple rotor engine having unequal firing intervals with the inherent disadvantages. Ideally, a triple rotary engine should have equal interval of firing ignition as exemplified in the U.S. Pat. No. 3,528,084, granted Sept. 8, 1970, to Hohenlohe wherein an integral three rotor engine is shown having its eccentrics rotatively offset by 120 degrees.
Accordingly, it is an object of this invention to provide a modular two-unit, rotary piston engine, which, without modification, can be easily coupled to a single unit rotary piston engine to create a triple engine having equal firing intervals and the smoothest possible output.
It is a further object of this invention to provide a modular two-unit, rotary piston engine which is separately, rotatively, dynamically balanced, which can be easily coupled to a single unit rotary piston engine which is similarly balanced to create a triple rotor engine having equal firing intervals and the smoothest possible output.
A still further object of this invention is to provide a triple rotor rotary engine having completely aligned rotor housings consisting of a modular, stand-alone two-unit, rotary piston engine coupled to a single unit piston engine which triple rotor engine achieves the smoothest possible output.
The foregoing and related objects are obtained in accordance with the invention which in its broader aspects provides a modular two-unit, rotary piston mechanism, each unit having a housing forming a cavity in which a rotor is eccentrically supported for planetary rotation so as to form a plurality of working chambers defined between the rotor and its housing which successively expand and contract in volumetric size as the rotor planetates relative to the housing. The housing is provided with an intake port means for introducing air into the working chambers and an exhaust port means for discharging products of combustion from the working chambers, a common mainshaft extending coaxially through the housing's cavities and having a pair of axially-shaped eccentric portions, one for each housing cavity. This pair of eccentric portions are rotatively offset 120 degrees.
In a narrower aspect of this invention, the intake port means of each housing are disposed one behind the other when viewed in a direction parallel to the shaft axis and where the exhaust port means of each housing are similarly disposed.
In another narrower aspect of this invention, a triple rotor engine is formed comprising the aforesaid two-unit engine and a single unit engine. The two-unit engine is coupled to the single unit engine in such a manner that the eccentric portion of the single unit engine is rotatively offset 120 degrees from the eccentrics of the two-unit engine.
Other objects of the invention will become apparent upon reading the specification taken in connection with the accompanying drawings.